Method of and apparatus for electric welding



E. L. SESSIONS.

METHOD 0F AND APPARATUS FOR ELECTRIC WELDING.

APPLICATION FILED SEPT. 27. 1919. RE11E\vED1uNE9.192o.

1,365,199. Patented Jan. 11,1921.

mi n Ww /ll//m 7 El" 46 4 5 "I7 4a 2 jazz/ewipe? F. L. SESSIONS.

METHOD 0F AND APPARATUS FORELECTHIC WELDING.

APPLICATIONFILED SEPT.27, 1919. HEHEWED JUNE 9,1920.

Patented Jan. 11, 1921.

4 SHEETS-SHEET 2.

F. L. SESSIONS.

METHOD OF AND APPARATUS FOR ELECTRIC WELDING.

APPLICATloNHLED'SEFTJL1919. REnEwr-:D IUNE 9.1920.

1 ,.865, 1 9 9. Patented Jan. 11, 1921.

4 SHEETS-SHEET 3.

F. L. SESSIONS.

METHOD 0F AND APPARATUS FOR ELECTRIC WELDING.

APPLICATION FILED SEPT.27. i919- RENEWED JUNE 9| 1920.

1,365,199. Patented Jan. 11,1921.

4 SIIEEIS-SHEET 4.

To all whom it may conce/Mi: I

- State of Ohio,

vPATENT OFFICE.

FRANK L. SESSIONS, OF LAKEWOOD, OHIO.

uE'rHoD or AND ArrAItATUs Fon ELECTRIC WELDING.

`Specification of Letters Patent.

Patented Jan. 11, 1921.

Application led September 27, 1919, Serial No. 326,774. Renewed June 9,1920. Serial No. 387,780,

Be it lmown that I, FRANK L. SESSIONS, a citizen of the United States,residing at Lakewood,inthe county of Cuyahoga and have invented certainnew Methods of and useful Improvements in and Apparatus for ElectricWelding, which the Vfollowing is a specification.

My invention relates to a method of and apparatus for electricallyweldinglap-seam or close-butted-'seam tubing to 'make what is knownV aselectrically welded seamless tubing. More, specifically, it relates to amethod of and apparatus for Welding the seam of aipreformed open-seamtube by electric currents induced in and made to flow circumferentiallyaround through the metal and across the lap-seam or closebutted seam ofsaid tubing by means of an alternating-magnetic field of force or aplurality of alternatingv magnetic fields, the magnetic lines of whichpass through the walls of the tubing and flowin'an axial directionthrough` thewspace .inclosed by the tubing. The alternating lines ofmagnetic force are set up by suitably dispod electric coils connected toalternating electric current circuits.

The broad Iprinciple of my invention is disclosed in my application,Serial No. 284,652, filed March 24, 1919. The present invention is `animprovement of the inven-l tion disclosed in theaforesaid application.

The objectv of my invention is the provision of a new and useful'methodand ap.

Vparatus for lapplying the principles em- .ployed-in welding tubingdisclosed inthe aforesaid v application.

'In the drawings: *c

'Figure l is a plan view of an apparatus suitable for carrying out my'method oi electrically welding tubing;

Fig. 2 is a section on line II-II of Fig-,3 is a- ,section on lineIII-III of ,Fig 1; .Y Fig. 4 is a diagram `of the electric andfma'gnetic l circuitsestablished in the operation oi the apparatus shownin Figs. 1, 2 and 3;

Fig. 5 isa `plan view of another form of apparatus suitable for carryingout my method offelectrically welding tubing;

Fig. 6 is a,section on line VIe-VI of Fig. 5;

Figs. 7 and 8 are respectively a plan view .and magnetic circuitsestablished in the operationl of the apparatus shown in Figs. 7 and 8;

Fig. 10 is a diagram showing the electric and magnetic circuits in themodification of the apparatus shown in Figs. 7 and 8;

Fig. 11 is a perspective diagram showing the direction of currentsinduced in the metal of a tube being welded by my method;

Fig. 12 is a conventional View of an apparatus for preforming open-seamtube from lat skelp prior to welding.

Referring to Figs. 1, 2, 3 andv 4 of the drawings, l represents a tubebeing welded in an apparatus which comprises a pair of laminated coresy2 and 3, each of which is provided with a series of poles, 4, 5, 6, 7and 8. The cores 2 and 3 are disposed with the faces of'their poles 4,5, 6, 7 and 8, in

l spaced-apart abutting relation to each other.

Electric coils, 9, 10,11 and 12, are placed upon the pole extensions, 5,5, and 7, 7. It is to be understood that all of the poles, 4, 5, 6, 7and 8, may have electric coils placed upon them, but I prefer thearrangement shown in Figs. 1 and 2, in which the poles, 5 and 7, aresalient poles and the poles, 4, 6 and 8, are consequent poles.

Through the space or opening between the poles of the laminated cores 2and 3, the open seam close-butted tube, 13, is made to traverselongitudinally of the tube by suitable mechanism, which will be.describd, pressure being applied to thewalls of the tubing to .make theabutting edges of the seam closely contact with each other. At the sametime that the tube is progressing through the space between thelaminated pole pieces alternating electric current is passed through theelectric coils, 9, 10, 11

induce electro-motive forces in the metal` wall of the tubing whichYcause' electric vcurrents to iiow circumferentially around the tubethrough the metal and across the seam thereof. These induced currentsheat the screws, 23 and 24. One of the feed' roller contacting surfacesof the opposite faces of the seam to a welding temperature and causethem to fuse or weld together.

For feeding or traversing the tube through the alternating magneticfields of force there may be provided feed-rolls such as shown at 14,15, which may be driven by'any suitable Adrivin connection from a powerdevice. In the rawings the rolls, 14 and 15, are shownl mounted upon andkeyed to vertical shafts or s indles, 16 and 17, which are gearedtogetlier by long-toothed spur gears, 18 and 19. .The spindles, 16 and17, are revolubly Amounted in adjustable bearings, 20 and 21, which aresupported in adjustable relation to each other by the bed late' orframe, 22, of the apparatus. Bearmgs, 20 and 21 are constructed to slidein vtransverse slots or guides \in the frame, 22, and means foradjusting the bearings and thereby adjusting the rollers, 14 and 15, isprovided in the form of ladjusting spindles, 17 is extended below itsspur gear, 19, and has mounted upon it and secured to it to rotate withit a bevel gear, 25, which meshes with a gear, 26, carried by thedriving shaft, 27, which is revo ubly. mounted in the adjustablebearilng, 28, and driven by a spur gear, 29.

-Only small transverse adjustments of the l feed, rolls, 14, and 15, arenecessary and these. adjustments are readily provided for by the longtoothed O'ears, 18 and 19, in a well-known manner. In order that thebevel gears, 25 and 26, may mesh properly for any adjusted psition ofthe s ur gears, 18,

' and 19, bearing, 28, is adjustab e in the wall of the frame, 22. Theadjustment of bearing, 28, is accomplished by means Iofl the screw.thread connection, 30, between the bearing 28, and a suitable hub, 31,on the frame,22.Y When the bearing, 28, has been properly adjusted it mabe secured in position by means of the ook nut, 32, shown inFigs. 1 and3.

To make pressure between the contactin surfaces of the seam there may beprovide pairs of adjustable pressure rolls such as Athose-shown at 34,35, 36 and 37. Each` 0f these rolls is revolubly mounted upon astationary cylindrical sleeve or trunnion,

f than t l A bolt,-39, passes through the sleeve, 38, and

38, slightly longer in its axial dimension e roller'which is mountedupon it.

-L together with the nut, 40, secures the sleeve,

.j l38, in the desired position forthe proper, 4adjustment of thepressure roll which it sup-v ports... The bolt, 39', '6o

asses through a slot, 41, in th`e frame, 22,0 the apparatus so that it,together'with the trunnion and pressure which it passes through may besecured .1' -per adjusted position. Set screws, 42,

priv'ded for eecfirigadjustment of the induced by the next precedingfield.

vide the armature or core, 45, of steel or 1ron to be inserted into thetube to extend past the faces of the poles, 4, 5, 6, 7 and 8. Means maybe proyided for holding the armature or core, 45, against longitudinaldisplacement, such means for instance, as

shbwn in Figs. 5, 8, 9, 10 and 12consisting of a bolt or rod secured tothe core, running longitudinally through the tubin and anchored to someexternal anchor. prefer, however, to provide no means for securing thecore, 45, in the tubing being welded other than the magnetic fields setup by current in the electric coils, 9, 10,

11 and 12, in pole pieces., 4, 5, 6, 7 and 8, andthe space between thepoles through which the tube 13, progresses.

As the end of the unwelded tubing is fed through Athe feed rolls, 14 and15, and enters -the magnetic field of the pole pieces, 4,circumferential currents will be set up in the tubing to heat the metalof the contacting faces of lthe seam. As the tube progresses through thesuccessive fields of alternating magnetic force other currents will beprogressively induced in the metal of the tube to add to the heatimparted by the currerllsts Y providing 'a plurality of magnetic fieldsand causing the tube to pass successively through these magnetic fieldsin the manner described, the heating of the tube can be moreeconomically and rapidljl effected than where-a single ma etic eld isemployed, and, consequently, t e speed of travel of the tube throughvthe apparatus, or, the speed of welding the tube may be much faster thanis possible where a single magnetic -field is employed. It will beunderstood by those skilled 1n the art that the electro-mo-l tive-forcegenerated inthe wall of the tubing tending to send electric currentcircumferentially through th'e metal of the wall of the tubing isproportional to the number per second of' lines of magnetic f o'rcethreaded throughy the electric circuit in which the electro-motive-forceis generated, Vand that the current w-hich lwill flow circumferentiallyaround through the wall of the tubing and across the seam will beproportional to this electro-motive-force and inversely proportional tolthe resistance of the electric circuit. It is obvious lthat fewer linesof force can be made to pass through the space inclosed by a tube osmall diameter than can be made to pass through a tube of relativelylarger diameter. It is obvious, therefore, that the heatingof the seamin a small tube will require more time than is required for a largetube. To overcome this diiiiculty in thel matter of welding small tubes,and, further, to increase the .speed of welding tubes of any diameter,I'have provided a plurality of magnetic fields through which the tubeprogresses successively. By providing such a plurality of magneticfields of forceI and causing the tube to pass progressively through themin s'uccessionthe necessary temperature for welding tubing of anydiameter may be attained, and the speed of travel of the tube throughthe welding apparatus may be increased with the number of magneticfields provided.

For securing the magnet cores, 2, 3, to the frame, 22, clamps, 46, andbolts, 47, may be employed. y

The frame, 22, is preferably made of brass or other non-magnetic metalas are also the pressure rollers, 34.

rlhe pressure l rollers perform another function besides that of makingpressure in that through their arcs of contact upon the tube they reducethe electrical resistance of the secondary or welding circuit of whichthe wall of the tube forms a part. The electrical resistance of the seamwill be greater than any other portion of the welding circuit and thegreatest heating will, therefore, occur at the seam.

InFigs. 5 and 6, there is shown an apparatus in which the magnet cores,48, 49, are each provided with only twopoles, 50l and 51. The electriccoils; instead of being disposed upon thepolar extensions of the coresare located upon the magnet yokes. A. single pair of pressure rollers,52, are employed, these pressure rollers being adjusted toward and fromeach other by means of adjusting screws, 53, and hand-wheels, 54. Acore, 55, of magnetizable material is shown secured in position by therod, 56, which may be anchored to anyl convenient external anchor, orthe core, 55, may have no anchor but be held in position solely by themagnetic field between the poles, 50 and 51. Any convenient means may beprovided for feeding or traversing the tube through the pressure rollsand the magnetic fields yof the ap-` paratus. In Figs. 7 and 8, areshown respectively a. plan and a side elevation of an apparatus in whicha single magnetcore, 57, having a pluralit of poles, is employed, itbeing mounted a jacent to one side of the tubing. Pressure rollers, orcombined pressure and .feed rollers, 58, 59, 60, 61, 62, and

63 may be employed for traversing the tub! ing through the magneticfields and for pressing the edges of the tubing firmly to' -7, 8 and 9,the electric coils, 65, 66, 67, 68

and 69 are shown wound upon the magnet yoke instead of yupon the polepieces.' 4If desired, the seam to be welded instead of being at the topof the tubev as it passes through the magnetic field may be at the sideor bottom thereof. For instance, Fig. 7 might be propcrlyreferred to asa side elevation and `ig. 8, a plan view of an apparatus in which thetube was being fed through the magnetic fields with the seam of the tubeat its side insteadof at its top. Further, the posi tion ofthe seam maybe in the plane of the magnet poles, or it may be in any other plane,provided only that the o posite edges of the seam Contact with each oter.

Fig. 9 is a diagram of the electric and magnetic circuits of theapparatus shown in Figs. 7 and 8, the tubing, 70 being shown in dottedoutline while the magnetizable core 64, is Shown in full lines. rlhedirection of the .electric currents induced in the wall of the tubin areshown bythe arrows, 71, 72, 73 74 an 75.

Fig. 10 is a diagram of an apparatus in which two magnet cores, 76 and77,-similar to magnet core, 57, are used. In this case the poles of themagnet cores are disposed on opposite sides of thetube in a mannersimilar to those shown inthe apparatus illustrated in Figs. 1, 2, 3 and4.

Fig. 11 is a perspective diagram showing the magnetic circuits andinduced electric currents in a tube which is being welded. Each of themagnet cores, 78 and `79, shown in Fig. 11 has three poles. -To avoidconfusion the electric coils are not shown' upon the poles of themagnets. .The polar-ities of the poles set up by a single alternation ofcurrent through the electric coils, which coils, it will be understood,are employed in tNhe apparatus, are shown by the letters,

The directions of the lines of magnetic force are shown by the dottedlines, 80 and 81. The directions of the circumferential currents inducedin the metal of the tube, 82, being welded are shown by the arrows, 83and 84. The seam of the tube is shown at 85 and a magnetizable armatureor core standing within the tube is shown at 86. y

It will'be understood that my method of and apparatus for welding tubingmaybe employed. for welding tubing which has been reviously rolled ordrawn into un` welded or open-seam tubing in a separate machine, or, theapparatus for carrying out Yskelp into open-seam tubing.

shown conventionally a In Fig. 12, I have 87, 88 and 89,

series of tube-forming rolls, in the operation of rolling the flatskelp, 90, into an open-seam tube, 91. Such an apparatus as I have shownin Figs. 1, 2 and 3, or, such as are shown in Figs. 5 and 6 may beemployed to receive and Weld the tubing, 91, as it emerges from therolls, 92. A ma netizable core, 93, may be employed, and it may beanchored as shown at 94. In fact, the core, 93, may serve not only toreduce the reluctance of the magnetic circuit, but it may also serve asthe mandrel upon which the tube, 91, is firmly rolled to the correctdiameter, by the rollers, 92.

Having thus described my invention, I claim and desirei to secure byLetters Patent:

1. The method of Welding together the contacting surfaces of an openseam in metal, which consists of passing. the metal successively througha plurality of fields of alternating magnetic force to cause alternatingcurrents of electricity to be induced in the metal and to oW across saidseam thereby heating the metal and Welding said seam together. 1

2. The method of Welding the contacting surfaces of an open seam inmetal, which consists of passing the metal successively through aplurality of fields of alternating magnetic force to cause alternatingcurrents of electricity to be induced in the metal and to fiow acrosssaid seam thereby heating said surfaces/to a Welding temperature, andsimultaneously applying pressure to said metal to cause the abuttingsurfaces of said seam to be pressed into contact with each other.

3. The' method-of Welding tubing which consists o f passing an open-seamtube, the

opposite edges of the seam of which are in contact with each other,successively through al plurality of fields of alternating magneticforce to cause alternating currents of electricity to be induced in themetal of said tube and to flow across said seam thereby heating the tubeand causing said seam to be welded together.

4. The method of -W-elding'tubing which consists of passing an open-seamtube successively through a plurality of fields of alternating magneticforce to cause alternating currents of electricity to flow across saidseam thereby heating the contacting surfaces of said seam to a weldingtemperature, and simultaneously applying pressure to said tube to causethe abutting surfaces of said seam to be pressed into contact with eachother.

5. In apparatus of the class described, an electric coil, means fortransmitting alternating current therethrough and means for traversing atube through the magnetic field field which is exterior to said coil.

6. In apparatus-of the class described, a plurality of electric coils,means for transmitting alternating current through each of said coils,and means for traversing a tube successively through the magnetic fieldsset yup by said current fiowing in said coils, said tube traversing onlyportions of said fields which are exterior to said coils.

7. In apparatus for electrically welding tubing, means for exciting aplurality of fields of alternating magnetic force and means for feedinga tube successively through said fields of force.

8. In apparatus for electrically Welding tubing, means for exciting aplurality of fieldsof alternating magnetic force, meansl for feeding ano en-seam tube successively through said fiel s of force, and means for-simultaneously applying pressure to said tube to cause the abuttingsurfaces of said seam to be pressed into contact with each other.

9. In aparatus for electrically welding the conta ng surfaces of an openseam in metal, an electric coil, means for transmitting alternatingcurrent therethrough, and 'means for feeding a metal object through themagnetic field set up by said current in said coil, said metal objecttraversing only a portion of said magnetic field which is exterior tosaid coil.

10. In apparatus for electrically welding the contacting surfaces of anopen seam in metal, an w,electric coil, means for transmittingalternating current therethrough, means for supporting the work outsideof said coil in the magnetic field set up by said current in saidA coiland means for causing relative movement of the work and said magneticfield longitudinally of the seam being welded.

11. In apparatus for electrically Welding the contacting surfaces of anopen seam in metal, an electric coil, means for transmitting electriccurrent therethrough, means for supporting the Work outside of said coilin the magnetic field set up by said current in said coil and means forcausing relative movement o f` the Work and said magnetic fieldlongitudinally of the seam being Welded.

12. In apparatus of the class described, means for exciting a rapidlyalternating field of magnetic' force, means for supporting the work vinsaid field outside of said exciting means, and means for causingprogressive relative movement between said work and saidfieldnlongitudinallykofsaid work.

plurality o alternately opposite, rapidly reversing polarity, and meansfor feeding the work past said pole faces parallel with itself andy withsaid pole faces. t

14. In apparatus for electrically welding the contacting surfaces of anopen seam in metal, means for vcausing the metal adjacent to the seambeing welded to be progressively traversed by a field of rapidlyalternating magnetic lines of force, and means for simultaneouslypressing said contacting surfaces together in saidv field of force.

15. In apparatus for electrically welding the contacting surfaces of anopen seam in tubing, an electric coil, means for transmitting electriccurrent through said coil, a magnetizable core forsaid coil having polesin close proximity to the tube to be welded, a magnetizable core in saidtube, and means for feeding the tube to be welded progressively throughthe field of magnetic force of said coil. i

16. In apparatus for electrically welding the contacting surfaces of anopen seam in metal, a plurality of spaced apart magnet poles, means forsupporting the work in the magnetic field adjacent to said poles, meansfor causing relative and`progressive movement of the work and saidmagnetic field,

and means for causing-rapid reversals ofv lmagnetism in said magneticfield.

In apparatus-for electrically welding the contacting surfaces of'a'nopen seam 1n metal, a plurality of spaced apart magnet poles, amagnetizable armature adjacent to but not in contact with said poles,and means for feeding the work throughthe space between said poles andsaid armature.

18. In apparatus for electrically weldingclose-butted, open-seam tubingto form electrically-welded, seamless tubing, a plurality of spacedapart magnet poles, a magnetizable armatureadjacent to said poles, saidarmature being adapted to pass longitudinally throu h the tube beingwelded, and means for ceding a tubelongitudinally of itself astfsaidpoles over said armature.

19. n apparatus for electrically welding close-butted, 4o en-seam tubingto form. electrically-welde seamless tubing, aplurality of spaced apartmagnet poles, a magnetizable armature adjacent to said poles, saidarmature being adapted to pass longitudinally throughthe tube beinwelded, means for feeding a tube longitu 'nally of itself past said-voles over said armature and means for simultaneously pressing vthecontactin 'surfaces of said seam together.

20. n apparatus forl electrically welding close-butte trically-welde i,seamless tubing, a plurality oxen-seam'tubing to form elecof spacedapart magnet poles, means for feeding a tube longitudinally of itselfpast said polesand a pair of pressure rollers, one

. on either side of said tube in contact with to force the contactingsurfaces of the seam thereof together.

22. In apparatus of the class described, a plurality of spaced apartmagnetic poles of rapidly alternating polarity, means for `feeding atubelongitudinally of itself successively past said poles and electricalconducting means electrically, circumferenti'ally in parallel with saidtube within the fielld of magnetic force emanating fromsaid po es.

23. In apparatus of the class described, a plurality of yspaced apartmagnetic poles of rapidly alternating polarity, means for feeding altube longitudinally of itself successively past said poles and a pair ofpressure rolls of electrical conducting material one on either side ofsaid-tube incontact therewith withinthe field of magnetic forceemanating from said poles.

24. In apparatus of the class described, a plurality of spaced apartmagnetic poles of rapidly alternating polarity, means for feeding a tubelongitudinally of itself successively past said poles, a pair ofpressure rolls of electrically conducting material one on either sideof'said tube in contact there- 4with within the field of magnetic forceemanating from' said poles 'and means for varying the pressure betweensaid tube and said rolls. j

25. In apparatusof the class described, a plurality of spaced apartmagnet .poles of rapidly alternating.: polarity, means for feedin a tubelongitudinally of itself successive y past said p'oles,- electricalconducting means electrically, circumferentially in parallel with saidtube within the field of magnetic force emanating from said poles andmeans for varying the contact pressure between said electricalconducting means and sai'd tube.

In testimony whereof I affix my signature.

FRANK i.. sessions.

